How to Use Adafruit ItsyBitsy nRF52840: Examples, Pinouts, and Specs

The Adafruit ItsyBitsy nRF52840 is a small and powerful microcontroller board that harnesses the capabilities of the Nordic nRF52840 chipset. This board is equipped with a 32-bit ARM Cortex-M4F processor, which provides ample computational power for a wide range of applications. With built-in USB support, Bluetooth Low Energy (BLE), and a rich set of I/O options, the ItsyBitsy nRF52840 is an ideal choice for projects that require wireless connectivity, such as wearable devices, smart home applications, and IoT prototypes.

• Wearable electronics
• Wireless sensor networks
• IoT devices
• Smart home automation
• Prototyping for Bluetooth-enabled products
• Educational projects and learning platforms

• Microcontroller: Nordic nRF52840
• Processor: ARM Cortex-M4F 32-bit processor with floating-point unit (FPU)
• Clock Speed: 64 MHz
• Flash Memory: 1 MB
• SRAM: 256 KB
• I/O Pins: 23 GPIO pins
• Analog Inputs: 6 (14-bit ADC)
• PWM Outputs: All GPIO pins support PWM
• Voltage Supply: 3.3V regulator with 600mA peak current output
• USB: Native USB support with onboard USB bootloader and serial port debugging

1. Powering the Board:

   • Connect a 3.7V LiPo battery to the VBAT pin for battery operation.
   • Alternatively, supply power via the USB port.

2. Programming the Board:

   • Connect the board to a computer using a micro USB cable.
   • Select the Adafruit ItsyBitsy nRF52840 board from your Arduino IDE or preferred development environment.

3. Connecting I/O:

   • Use the GPIO pins for digital input and output.
   • Analog pins A0-A5 can be used for analog sensors.
   • PWM functionality is available on all GPIO pins for controlling motors or LEDs.

• Always ensure that the power supply is within the specified range to prevent damage.
• When using the board with a battery, monitor the battery voltage to avoid deep discharge.
• Use appropriate pull-up or pull-down resistors with inputs to ensure defined logic levels.
• Avoid drawing more than the maximum current from the 3.3V regulator.
• When using BLE, follow best practices for wireless communication, such as proper antenna placement.

• Board not recognized by the computer:

  • Ensure the micro USB cable is properly connected and the board is powered on.
  • Try using a different USB port or cable.

• Failure to upload sketches:

  • Check that the correct board and port are selected in the development environment.
  • Press the reset button twice quickly to enter bootloader mode if necessary.

• Inconsistent behavior when running on battery:

  • Verify that the battery is charged and functioning correctly.
  • Check for proper connection at the VBAT pin.

• Always start with simple blink sketches to ensure the board is functioning correctly.
• Use serial debugging to print out status and error messages.
• Consult the Adafruit forums and online resources for community support.

• Can I use the ItsyBitsy nRF52840 with Arduino IDE?

  • Yes, you can program the board using the Arduino IDE by adding the Adafruit board support package.

• Does the board support over-the-air (OTA) updates?

  • Yes, the nRF52840 chipset supports OTA updates, which can be implemented using BLE.

• What is the maximum range of the BLE on this board?

  • The range depends on many factors, including antenna design and environmental conditions, but typically it can be up to 100 meters line-of-sight.

Here is a simple example of how to blink the onboard LED using the Arduino IDE:

// Define the LED pin
#define LED_PIN 13

void setup() {
  // Set the LED pin as an output
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  // Turn the LED on
  digitalWrite(LED_PIN, HIGH);
  delay(500); // Wait for 500 milliseconds

  // Turn the LED off
  digitalWrite(LED_PIN, LOW);
  delay(500); // Wait for 500 milliseconds
}

Remember to select the Adafruit ItsyBitsy nRF52840 board from the board manager before uploading the code. This example will toggle the onboard LED every half-second, serving as a basic test to ensure your board is working correctly.